Study designs of evaluations included in the review
Primary studies other than case series or case reports were eligible for inclusion.
Specific interventions included in the review
Studies of isotretinoin treatment of acne were eligible for inclusion. Studies of isotretinoin for other indications were excluded. The included trials compared different isotretinoin dose regimens, whereas the observational studies either compared isotretinoin with oral antibiotics or had no comparator group. Doses of isotretinoin, where reported, varied from 0.1 to 2 mg/kg per day to 40 mg per day. The duration of treatment was 16 weeks in most of the studies that reported it; one study reported a mean duration of 20 weeks.
Participants included in the review
Studies in patients with acne vulgaris were eligible for inclusion. Studies with fewer than 20 participants were excluded. The participants included in each study were not described.
Outcomes assessed in the review
Studies that reported at least one of the following as a primary outcome were eligible for inclusion: depressive symptoms, depression diagnosis, suicide attempt or completed suicide. The included studies used different assessment tools, including various standard psychiatric questionnaires, International Classification of Disease codes, symptom and adverse event questionnaires, patient interview, and prescription sequence symmetry analysis. Follow-up was limited to the 16-week (or 4- month) treatment period in five studies; in one study it was at least 6 months before treatment to 12 months after the last prescription; in the other studies it was either 10 months, 6 months, at the end of treatment, or not stated.
How were decisions on the relevance of primary studies made?
It appeared that one reviewer selected the studies and a second reviewer, who applied the inclusion criteria independently, resolved any uncertainties.